Article View: sci.electronics
Article #7537Re: LED flasher
From: Electric Blue
Date: Mon, 01 Oct 1990 23:51
Date: Mon, 01 Oct 1990 23:51
47 lines
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2293 bytes
In article <1990Sep30.043045.22757@sisd.kodak.com>, rg@sisd.kodak.com (Rich Gortatowsky) writes:
>
> I am a auto modeler and wish to add blinking lights (ie: turn signals)
> to a model. I have the LED's all set and working for running lights etc.
> How... preytel... does one make a "flasher". I'm basically using only
Just use a flashing led. They look just like a normal led and are available
for under $1. Looking at the Radio Spares catalogue they are available in
red, green or dual colour. Just connect power and flash away.
> 2 volts er so imput current. I assume there is a simple (cheap?) way?
> Does it require a relay? If so... well... A simple? diagram of such a
> circuit would be most appreciated!
If you really want to build your own cct you can use an LM3909N led flasher
ic made by National Semiconductors. These retail for about $1.50 and run
on 1.5 to 3V. the cct is as follows:
+------------------+
| ________ | LED
+-----|1 8|-----+---|<---+
+-||--|2 7| |
C1 |3 6|--------------+
+---|4 5|---+
| -------- |
| |
| V- V+ |
+--- ---+
C1 is 300 uf for a flash rate of 1HZ. To have a faster rate simply decrease
the value of C1. LED can be any normal led. The cct uses the voltage across
the timing capacitor C1 as a boost voltage so it can flash green leds from
a supply voltage of as low as 1.5V.
>
> THanks!
>
Hope the above helps.
>
> --
Login name: gz In real life: George Zisis
+61 2 415 0515 (RTC, CSC, RTOC, or any other acronym you care to think of..)
-m---------- Pyramid Technology Australia
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<1803@pta.oz.au>Path:
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<1990Sep30.043045.22757@sisd.kodak.com>Show Full Headers
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Path: arc1-ca.pugleaf.net!utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!munnari.oz.au!mel.dit.csiro.au!yarra!pta!gz From: gz@pta.oz.au (Electric Blue) Newsgroups: sci.electronics Subject: Re: LED flasher Summary: just use a flashing led Message-ID: <1803@pta.oz.au> Date: 1 Oct 90 23:51:58 GMT References: <1990Sep30.043045.22757@sisd.kodak.com> Organization: Pyramid Technology Corporation, Sydney Lines: 47